This information is needed in the estimation of S2d_i (Eberhart and Russell, 1966 1 ) and Lambda_i (Tai, 1971 2 ), as well as in the test of significance of each IPCA from the linear-bilinear model.
Eberhart S A & Russell W A. (1966) Stability parameters for comparing varieties. Crop Science 6 :36-40.
Tai, C.C.G. (1971) Genotypic Stability Analysis and Its Application to Potato Regional Trials. Crop Science 11 (2): 184-190.